Scanning probe microscopy (SPM) devices, such as atomic force microscopy (AFM) devices, are for example applied in the semiconductor industry for scanning of semiconductor topologies on a surface. Other uses of this technology are found in biomedical industry, nanotechnology, and scientific applications. In particular, AFM may be used for critical dimension metrology (CD-metrology), particle scanning, stress- and roughness measurements. AFM microscopy allows visualization of surfaces at very high accuracy, enabling visualization of surface elements at sub-nanometer resolution.
As a result of the high accuracy, conventional and available SPM devices are to be controlled precisely, and contain accurate and sensitive measuring equipment, as well as positioning and scanning equipment arranged for supporting the very high (e.g. sub-nanometer) resolution. Correct calibration of the device parts and the use of a high resolution positioning feedback system enable the SPM device to provide the required accuracy, although all these measures come at a cost.
A disadvantage, for example, is that SPM devices are usually limited to inspection of relatively small substrate surfaces. This is because it is much more easy to obtain the required accuracy with a positioning structure having a small stroke (e.g. enabling to move the probe head across a distance of e.g. 10 cm) than to obtain the same accuracy with a positioning system having a large stroke (enabling to move the probe head across a distance of e.g. 100 cm). This is because the positioning and metrology loops are typically much larger for systems with large strokes. A larger positioning loop means more compliance in actuated parts and loss of accuracy. A larger metrology loop means more compliance in general and therefore more vulnerability to disturbances.